GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 45101-100 Conical Brake Rotor Washers

Adjustment Procedure

    Important: Brake rotor thickness variation greater than the specification can cause brake pulsation.

  1. Measure the brake rotor thickness variation. Refer to Brake Rotor Thickness Variation Measurement .
  2. Important: Brake rotor assembled lateral runout (LRO) greater than the specification can cause brake pulsation.

  3. Measure the brake rotor LRO. Refer to Brake Rotor Assembled Lateral Runout Measurement .

  4. Object Number: 891801  Size: SH
  5. Remove the J 45101-100 and the wheel nuts.
  6. Remove the rotor from the hub.
  7. Rotate the rotor 1 wheel stud position (72 degrees).
  8. Install the rotor to the hub.
  9. Hold the rotor firmly against the hub. Install one of the J 45101-100 and 1 wheel nut on the top wheel stud.
  10. Continue to hold the rotor and tighten the wheel nut by hand.
  11. Install the remaining J 45101-100 and the wheel nuts.
  12. Tighten the wheel nuts firmly by hand in a star pattern.
  13. Notice: Refer to Fastener Notice in the Preface section.

  14. Tighten the wheel nuts in a star pattern in order to retain the rotor to the hub. Refer to Fastener Tightening Specifications .
  15. Measure the brake rotor LRO. Refer to Brake Rotor Assembled Lateral Runout Measurement .
  16. If the brake rotor LRO is greater than the specification, repeat this procedure with the rotor at the remaining 3 wheel stud positions.
  17. If the brake rotor LRO is greater than the specification at all 5 wheel stud positions, use an on-vehicle lathe in order to reduce the brake rotor LRO to the specification. Refer to Brake Rotor Assembled Lateral Runout Correction - On Vehicle Lathe .
  18. If the brake rotor LRO is less than the specification, complete the following steps:
  19. • Use paint in order to mark the position of the brake rotor on the hub.
    • Install the brake caliper.
    • Press the brake pedal several times in order to position the brake rotor.
    • Remove the wheel nuts.
    • Remove the J 45101-100 .
    • Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .